scholarly journals Testing the Competence of Cimex lectularius Bed Bugs for the Transmission of Borrelia recurrentis, the Agent of Relapsing Fever

2019 ◽  
Vol 100 (6) ◽  
pp. 1407-1412 ◽  
Author(s):  
Basma El Hamzaoui ◽  
Maureen Laroche ◽  
Yassina Bechah ◽  
Jean Michel Bérenger ◽  
Philippe Parola
2021 ◽  
pp. 146960532199394
Author(s):  
Venla Oikkonen

This article explores the conceptual and cultural implications of using pathogen ancient DNA (aDNA) collected in archaeological contexts to understand the past. More specifically, it examines ancient pathogen genomics as a way of conceptualizing multispecies entanglements. The analysis focuses on the 2018 sequencing of Borrelia recurrentis bacteria retrieved from a medieval graveyard in Oslo, Norway. B. recurrentis is associated with louse-borne relapsing fever (LBRF), known to have killed several million people in Europe during the past millennium, and it is still encountered in parts of East Africa. The article demonstrates that while aDNA research often foregrounds multispecies entanglements, its epistemic tools cannot easily address the ontological blurriness of pathogens and their embeddedness in vibrant material processes. The article draws on feminist posthumanities work on microbes and materiality to highlight conceptual openings that a theorization of ancient pathogens could engender.


Author(s):  
Mohammad Akhoundi ◽  
Dahlia Chebbah ◽  
Denis Sereno ◽  
Anthony Marteau ◽  
Julie Jan ◽  
...  

Bed bugs, Cimex lectularius and C. hemipterus, are common blood-sucking ectoparasites of humans with a large geographical distribution, worldwide. In France, little is known about the status of bed bugs’ infestation and their resistance to insecticides, particularly, pyrethroids. Here, we aimed to find mutations in the kdr gene, known to be involved in resistance to insecticides. We gathered bed bugs from various infested locations, including 17 private houses, 12 HLM building complex, 29 apartments, 2 EHPAD, and 2 immigrants’ residences. A total of 1211 bed bugs were collected and morphologically identified as C. lectularius. Two fragments of the kdr gene, encompassing codons V419L and L925I, were successfully amplified for 156 specimens. We recorded sense mutation in the first amplified fragment (kdr1) in 89 out of 156 (57%) samples, in which in 61 out of 89 (68.5%) sequences, a change of valine (V) into leucine (L) V419L was observed. Within the second fragment (kdr2), a homozygous mutation was recorded in 73 out of 156 (46.7%) specimens at the codon 925. At this position, 43 out of 73 (58.9%) specimens had a sense mutation leading to the replacement of leucine (L) by isoleucine (I). Among 162 mutant sequences analyzed (89 for the kdr1 fragment and 73 for the kdr2 one), we detected single point mutation in 26.6%, while 73.4% presented the mutation in both kdr1 and kdr2 fragments. All modifications recorded in bed bug populations of Paris are described to be involved in the knockdown resistance (kdr) against pyrethroids.


Author(s):  
Raymond Berry

AbstractThe bed bug, Cimex lectularius L., is a common ectoparasite found to live among its vertebrate hosts. Antennal segments in bugs are critical for sensing multiple cues in the environment for survival. To determine whether the thermo receptors of bed bugs are located on their antennae; innovative bioassays were created to observe the choice between heated and unheated stimuli and to characterize the response of bugs to a heat source. Additionally, the effect of complete antenectomized segments on heat detection were evaluated. Heat, carbon dioxide, and moisture are cues that are found to activate bed bug behavior; a temperature at 38°C was used to assess the direction/degree at which the insect reacts to the change in distance from said stimulus. Using a lightweight spherical ball suspended by air through a vacuum tube, bed bugs and other insects are able to move in 360° while on a stationary point. Noldus EthoVision XT was used to capture video images and to track the bed bugs during 5-min bioassays. A bioassay was created using four Petri dish arenas to observe bed bug attraction to heat based on antennae segments at 40°C. The purpose of this study was to evaluate the effects of heat on complete antenectomized segments of the antennae. The results in this experiment suggest that bed bugs detect and are attracted to heat modulated by nutritional status. Learning the involvement of antennae segments in heat detection will help identify the location and role of thermoreceptors for bed bug host interaction.


2020 ◽  
Vol 57 (3) ◽  
pp. 969-973 ◽  
Author(s):  
Juan Carlos Cambronero-Heinrichs ◽  
Laura Sofía Sánchez-Portilla ◽  
Ólger Calderón-Arguedas ◽  
Adriana Troyo

Abstract Cimex lectularius and Cimex hemipterus are the most common species of bedbugs that infest homes. Although case reports decreased substantially by the end of the 20th century, bed bugs, and especially C. lectularius, are currently suffering a resurgence mostly attributed to insecticide resistance, inadequate pest control, and increased travel. Here, we report, to the best of our knowledge, the first molecular confirmation of C. lectularius in Central America. Specimens were obtained from an apartment located in Heredia, Costa Rica. These specimens were identified morphologically as C. lectularius. The species identification was confirmed by amplifying and sequencing fragments of the cytochrome oxidase subunit I (COI) and the 16S rRNA (16S) genes. The phylogenetic analysis showed that the sequences obtained were more closely related to a C. lectularius mitochondrial complete genome sequence from China, with similarities of 98.84% (686/694) for COI and 98.97% (387/391) for 16S. The finding of C. lectularius in Costa Rica will require further investigation in order to determine the extent of current infestations and the susceptibility to insecticides, especially due to the impact that this species can have in human health, as well as the tourism industry in the region.


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